Factors determining gender ratio in the Maltese population

Introduction: The Male/Female ratio at birth has been described to favour the male conceptus, a situation that persists throughout most of childhood and into the reproductive phase of life. The reasons behind this preferential male-favouring remain elusive. Methodology: The various relevant obstetric and population national registers kept by the Department of Health information and the National Statistics Office of the Maltese Islands were reviewed to elucidate the age-related M/F ratios differences in the population starting with the third trimester of the antenatal period. In addition, third trimester M/F ratios in women with specific metabolic-related disorders were assessed and compared to the on-affected individuals. The role of foetal congenital malformations was also investigated. Results: It would appear that the M/F ratio starts favouring the male conceptus as early as the third trimester of the antenatal period. It remains favoured right through the reproductive age reaching par after the age of 45 years when it shifts to favour the female. This relationship was significantly altered during the 1930s as a result of the emigration patters prevalent during that period. The results further show that the maternal nutritional and biochemical milieu may influence the M/F ratio at the beginning of the third trimester with women suffering from adiposity, diabetes and thyroid disease having higher M/R ratios. In spite of this preference to the male conceptus, malts have a higher mortality throughout life with mortality rates being higher for males from the third trimester up to the age of 75 years. On the other hand, female foetuses with malformations appear to have a higher mortality during intrauterine life than corresponding male foetuses. Conclusion: The M/F ratio appears to favour the male conceptus during antenatal life and is definitely evident by the beginning of the third trimester of pregnancy, the selection mechanism possibly being a greater predisposition of female foetal loss in the presence of malformations. These biological observations may present advantages within the breath of human reproductive ecology, ensuring a healthy reproductive female individual who has the option of choosing her mate from a competing male community.peer-reviewe

Effect of interface disorder on quantum well excitons and microcavity polaritons

The theory of the linear optical response of excitons in quantum wells and polaritons in planar semiconductor microcavities is reviewed, in the light of the existing experiments. For quantum well excitons, it is shown that disorder mainly affects the exciton center-of-mass motion and is modeled by an effective Schroedinger equation in two dimensions. For polaritons, a unified model accounting for quantum well roughness and fluctuations of the microcavity thickness is developed. Numerical results confirm that polaritons are mostly affected by disorder acting on the photon component, thus confirming existing studies on the influence of exciton disorder. The polariton localization length is estimated to be in the few-micrometer range, depending on the amplitude of disorder, in agreement with recent experimental findings.Comment: To appear in Journal of Physics: Condensed Matte

Spontaneous symmetry breaking in a quadratically-driven nonlinear photonic lattice

We investigate the occurrence of a phase transition, characterized by the spontaneous breaking of a discrete symmetry, in a driven-dissipative Bose-Hubbard lattice in presence of two-photon coherent driving. The driving term does not lift the original $U(1)$ symmetry completely and a discrete $\mathbb{Z}_2$ symmetry is left. When driving the bottom of the Bose-Hubbard band, a mean-field analysis of the steady state reveals a second-order transition from a symmetric phase to a quasi-coherent state with a finite expectation value of the Bose field. For larger driving frequency, the phase diagram shows a third region, where both phases are stable and the transition becomes of first order.Comment: 7 pages, 3 figures, version accepted for publicatio

Hospitaller activities in medieval Malta

The Medieval Period in the Mediterranean World is generaly considered to cover a period of about a thousand years, and is considered to initiate with the end of the Roman era heralded by the division of the Roman Empure into two parts between the sons of Theodosius in AD 395. It ended with the advent of the Renaissance movement of the fifteenth century. This period in Malta was to see the Islands come under the influence of the Byzantine Empire encompassing the period prior to the ninth century; the Arab dominance starting in AD 870 and lasting until their formal expulsion in the mid-13th century; and the Latin phase of the late 13th century to the early 16th century when the islands were ceded to the Order of St. John of Jerusalem. The documentary sources dated to before the 14th century are rather scanty and often limited to ecclesiastical and political matters. A number of extant documents relate to medical matters, particularly with the setting up and management of hospital services and with matters relating to the affairs of hospitaller orders having links to the Maltese Islands.peer-reviewe

War and population change in the Maltese context

Warfare is associated with marked social consequences that directly and indirectly will influence the reproductive patterns of the population. The present analysis looks at the population changes that occurred during the three of the four major conflicts where the Maltese population was directly involved. The study confirms that one of the consequence of warfare in the Maltese context during the centuries was a reduction in birth rates that picked up again in the post-war period.peer-reviewe

A maternity unit in Gozo a hundred years ago

The present paper reviews the hospital confinements which occurred at Victoria Hospital in Gozo during the period 1876-1893. These hospital confinements are shown to have been generally restricted to needy women from the lower socio-economic strata. The lower socio-economic status of these mothers, together with the fact that these mothers were more likely to have significant medical and/or obstetric problems, resulted in higher perinatal and maternal mortality rates than those reported for the general population in Gozo and Malta. These observations are in conformity with the maternity care situation in European establishments.peer-reviewe

Nineteenth-century disciplinary enquiry at Victoria Hospital, Gozo

In this article the author presents a report which describes an enquiry into the actions of a junior medical practitioner employed with the public sector in the late nineteenth century, wherein the final intention was in disciplining the officer without attempting to correct the circumstances which led to the incident. An account of the case which provoked the disciplinary enquiry is described in the article.peer-reviewe

Dr. James Barry : an enigmatic army medical doctor

In spite of marked eccentricity, Dr. Barry became notorious only after dying on 25th July 1865. The Irish newspaper Saunders’s News Letter on 14th August 1865 reported Dr. Barry’s death and revealed that the doctor was in fact a female who had masqueraded as a male throughout her life. Dr. Barry had served as a principal medical officer with the British Military in Malta for about four and a half years. An eccentric but very professionally able person, Dr. Barry joined the Army Medical Department as a hospital assistant on 5th July 1813 and subsequently practiced for the benefit of soldiers in Plymouth, South Africa, Jamaica, St. Helena and Barbados before being posted to Malta on 2nd November 1846. Through her subterfuge, Dr. James Barry had made history by being the first woman in Britain to graduate as a medical doctor and to fulfil an active army career dedicated to Medicine and the amelioration of human suffering. Whatever the reasons for the subterfuge, Barry, during her forty-six years service showed herself to be a successful doctor and administrator.peer-reviewe